xref: /openbmc/linux/arch/arm64/include/asm/fixmap.h (revision 4f3db074)
1 /*
2  * fixmap.h: compile-time virtual memory allocation
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 1998 Ingo Molnar
9  * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
10  *
11  * Adapted from arch/x86_64 version.
12  *
13  */
14 
15 #ifndef _ASM_ARM64_FIXMAP_H
16 #define _ASM_ARM64_FIXMAP_H
17 
18 #ifndef __ASSEMBLY__
19 #include <linux/kernel.h>
20 #include <asm/page.h>
21 
22 /*
23  * Here we define all the compile-time 'special' virtual
24  * addresses. The point is to have a constant address at
25  * compile time, but to set the physical address only
26  * in the boot process.
27  *
28  * These 'compile-time allocated' memory buffers are
29  * page-sized. Use set_fixmap(idx,phys) to associate
30  * physical memory with fixmap indices.
31  *
32  */
33 enum fixed_addresses {
34 	FIX_HOLE,
35 	FIX_EARLYCON_MEM_BASE,
36 	FIX_TEXT_POKE0,
37 	__end_of_permanent_fixed_addresses,
38 
39 	/*
40 	 * Temporary boot-time mappings, used by early_ioremap(),
41 	 * before ioremap() is functional.
42 	 */
43 #ifdef CONFIG_ARM64_64K_PAGES
44 #define NR_FIX_BTMAPS		4
45 #else
46 #define NR_FIX_BTMAPS		64
47 #endif
48 #define FIX_BTMAPS_SLOTS	7
49 #define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
50 
51 	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
52 	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
53 	__end_of_fixed_addresses
54 };
55 
56 #define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
57 #define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
58 
59 #define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
60 
61 void __init early_fixmap_init(void);
62 
63 #define __early_set_fixmap __set_fixmap
64 
65 #define __late_set_fixmap __set_fixmap
66 #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
67 
68 extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
69 
70 #include <asm-generic/fixmap.h>
71 
72 #endif /* !__ASSEMBLY__ */
73 #endif /* _ASM_ARM64_FIXMAP_H */
74